Exam 4 fast Flashcards
Gram negative diplococcic cells in CNS
Treat with intravenous penicillin
Meningitis
Diplocci observed in dishcarge
Oxidase test for cytochrome c oxidase comes up purple (positive)
Gonorrhea
Mutualistic function of E. coli
vitamin K production
Organism is a gram negative rod and exotoxin are identifiable
Patient likely has gastroenteritis
virulence genes on plasmids
Typical E. coli
Non-invasive E. coli infection
Causes traveller’s diarrhea
treat with rehydration and pepto
Entertoxigenic E. coli
E. coli causes dysentery like disease that invades intestinal wall causing inflammation and fever
Enterinvasive E. coli
E. coli responsible for infant diarrhea
Enteropathogenic E. coli
E. coli causes hemorrhagic colitis and is associated with hemolytic uremic syndrome in children and elderly
Enterohemorrhagic E. coli
Bacteria is gram negative, non-motile rod. Its capsule protects from phagocytosis. This capsule give the colony a mucoid appearance.
Normal skin microbiota
Klebsiella pneumonia
When grown at room temperature this organism produces a red pigment.
Can grow in saline and is opportunistic of the immunocompromised in urinary and respiratory tracts
Serratia marsecans
Gram negative organism with gliding motility
Found on any dead and decaying matter
Rapid urease test result
Proteus mirabilis
Type III secretion systems inject proteins that inhibit phagocytosis, rearrangeeukaryotic cytoskeletons, or induce apoptosis
Truly pathogenic enterbacteriaceae
Typhoid fever
Gastroenteritis (and bacteria can get to blood through ulcerations)
Survives phagocytosis
Salmonella typhi
gram negative rod
fever, cramps, vomiting
organism can punch through epithelial walls and into blood stream
Salmonella typhimurium salmonellosis
Re-hydration and 250+ doses of chloramphenicol
removal of gal bladder
S. Typhi treatment
Gram negative and non-motile
the toxin typically induces diarrhea
Genus can cause dysentary
Shigella
High fever, swollen lymph nodes (buba)
Yersinia Pestis
Bubonic plauge
gram negative rod
Rapidly developing lung infection
Poor hygiene and possibly fleas
Yersinia Pestis
Pneumonic plague
gram negative rod causing intestinal inflammation
Yersinia enterocolitica
Small pleomorphic (no set shape) bacilli Obligate parasite (requires heme and NAD+ for growth)
Haemophilus
Common form of meningitis of infants
Can cause skin infections, sepsis, etc…
Haemophilus influenza
Gram negative, non motile, short rods
Organism uses filamentous hemagglytinin to attach to ciliated epithelia in lungs (toxin helps and deters phagocytes)
Signature symptom in patients, limited response to antibacterials
Bordetella pertussis
Whooping cough
gram negative, motile, rod
opportunistic of immune-compromised patients and able to colonize almost any organ
capsule with numerous
produces a biofilm capable of gene transfer
Tests catalase positive
beta hemolytic on blood agar
produces pyocyanin
Pseudomonas aeruginosa
fimbriae and adhesins for attachment.
toxins inhibit protein synthesis in eukaryotic cells
Predominantly colonize respiratory track
invades and proliferates in phagocytes
causes pontiac fever and its namesake disease
Legionella pneumophila
gram negative, motile, oxidase positive, curved rod
salt tolerant (and some require it)
“rice water diarrhea”
Vibrio cholera
This toxin has two subunits, a and b. a1 triggers enzyme cascade converting AMP to cAMP in epithelial cells
Cholera toxin
gram negative, motile, oxidase positive, curved rod
salt tolerant
Causes gastroenteritis and wound infections and can result from bad shellfish
Vibrio parahaemolyticus
gram negative, motile, oxidase positive, curved rod
salt tolerant
Can result from washing wounds in sea water. Wounds take form of blistering dermatitis
Vibrio vulnificus
Organism has no cell walls
Two membranes without peptidoglycan between them
Obligate intracellular parasite that needs to be inside the phagosome
Chlamydia
Chlamydia life cycle
Elementary body (EB) attaches to host cell receptor enters via endocytosis converts to Reticulate body (RB) in food vesicle rapid division, some switch back to EB before cell ruptures
Only two known hosts; us and mice
Infects conjunctiva of the eye which scars and eyelashes turn backward which abrades the eyes
can infect newborns at birth or transmission by flies
Chlamydia trachomatis
Small painless lesions around genitals
Painful urination and intercourse
may cause buboes
Most common STD
Chlamydia LGV
General characteristics of a Eukaryote
Membrane bound organelles
80s ribosome
nucleus
undulating flagella
Haploid and diploid refer to
the number of complete copes of the cell’s genome
1 and 2
Interphase
Step 1
DNA replicates
Mitosis
Step 2
an equal partitioning of replicated DNA between two nuclei
2n to 2n
Cytokinesis
Step 3
cytoplasmic division
cleavage or in the case of yeast, budding
Meiosis
An equal partitioning of replicated DNA between four nuclei
2n to 1n
Schizogony
Multiple rounds of mitosis form a multinucleate cell called a schizont
Multiple rounds of (mitoses and) cytokinesis form several merozites
occurs mostly in parasitic protozoans
Protozoa
Unicellular
ubiquitous
motile (pseudopodia, cilia, flagellum)
Protozoan nutrition
Most are chemo-organo-heterotrophs Predators of bacteria and each other Feed on decaying organic matter Consume host tissues Some are photosynthetic while others are mixotrophs (both)
Trohpozoite
Free living motile feeding stage of a protozoan
Cyst
resting stage that allows cells to survive unfavorable conditions
not a reproductive structure
pass from intestines of one host to another
Dinoflagellates (phylum)
Two (unequal in length) flagella:
- Transverse (spin)
- Longitudinal (propulsion)
Gonyaulax (genus)
Produce yessotoxin (kills fish at high concentrations)
If highly concentrated in shellfish then it can harm humans
Photosynthetic red pigments (cause of red tide)
Pfiesteria (genus)
Possible estuary associated syndrome (PEAS)
produce potent neurotoxin
parasite of fish
Chagas Disease
Trypanosoma Cruza = kinetoplastid: organism with a single large mitochondrion
Zoonotic reservoirs: opossums and armadillos
transmission by kissing bug
Stages of Chagas disease
Acute: swellings (chagomas) occur at site of bite
Generalized: fever, swollen lymph nodes, heart inflammation
Chronic: asymptomatic (months to years)
Symptomatic: heart failiure
Chagas disease diagnosis and treatment
xenodiagnosis: allow kissing bug feeding of patient, then disect for evidence of growth 4 weeks later
Treat early stages with antiparasitic: benznidazole, nifurtimox (60% cure rate)
Later stages require surgery and transplant
lives in intestines of humans and animals
four pairs of flagella
Two equal sized nuclei
Form cysts and have an adhesive disk (organism resembles ToV boss)
Giardia intestinalis
Giardia intestinalis life cycle
ingestion of cysts: fecal oral or water
Cysts release a trophozoite when activated by stomach acid which enters intestines
Often asymptomatic
can cause severe watery diarrhea, ab pain, nausea, vomiting, foul-smelling stool (rotten egg)
Usually 1-4 weeks, but can be reinfected (dog eating poop)
Beaver fever
Giardiasis
Infects olfactory nerve and can spread up to brain (inhaled trophozoites from water)
Primary: loss of smell, headavhe, fever, vomiting, stiff neck (3-5 days)
Secondary: hallucinations, confusion, ataxia (loss of muscle control)
Death within 3-7 days or primary symptoms
Amoebic Meningoencephalitits
Naegleria fowleri
Chitin in the cell wall?
Must be a fungi
Yeast
small, globular, single cells
Mold
Long branched tubular hyphae
Mycelium
Intertwined mass of hyphae (can even become visible to unaided)
Fungi reproductive structures
Yeasts: buds
Mushrooms and molds: spores (sporangia, conidia, basidia) easily dispersed
Chlamydospore: resting structure that survives unfavorable conditions
Haustoria
structure that allows a fungi to obtain nutrients from a living organism (modified hyphae)
Commonly found in moist soils with high N levels (bat caves)
Two strains / variants
Histoplasma Capsulatum:
- Var. capsulatum
- Var. dubiosii
True pathogen
Fungal disease that resembles tuberculosis
Does not typically infect the healthy
severe coughing, bloody sputum
Histoplasmosis
H. capsulatum
culture and observe morphology Hyphae seen at <30C and spiny spores yeasts grow at 37C Treatment: ketoconazole amphotericin B
Histoplasmosis
Ketoconazole
prevents formation of fungal cell membrane (ergosterol)
amphotericin B
punches holes in fungal cell membranes
True pathogenic fungi
Blastomyces dermatidis
Coccidiodes immitis
Histoplasma capsulatum
Paracoccidiodes brasiliensis
One of the few fungi to be transmitted from person to person
Normal microbiota of skin
Candida albicans
white plaque in the mouth
cloudy vision and lesion within the eye
Yeast infections: prolific growth after normal bacterial microbiota are disrupted (change in vaginal pH)
Candidiasis
(___) administered nystatin (works like amphtericin b)
(___) use of azole creams and suppositories or oral fluconazole
Orally
Vaginal
ubiquitous and opportunistic pathogen of potentially anywhere on the body
Typically molds fruits
Aspergillus niger
hypersensitivity:
asthma or allergic reactions to inhaled spores
non-invasive: ball like masses of hyphae in lungs (aspergillomas) [asymptomatic]
acute-invasive: severe lung damage (surgical action necessary)
Aspergillosis pulmonary
Fungal growth in sinuses, ear canals, conjunctivas
Aspergillosis non-pulmonary
bacteriophage
insert genetic material directly into host cell
dsDNA
d20 on a pillar with legs
Animal viruses
Entire virus is taken in by cell, often have an envelope
glycoprotein spikes instead of tails
direct entry
a pore is created for the viral genome
membrane fusion
two membranes come together and fuse (like liquid drops). A hole is created for the capsid to insert
endocytosis
entire virus is endocytized
DNA viruses use the (___) to replicate while RNA viruses use the (___)
nucleus
cytoplasm
dsDNA pleomorphic capsule and envelope infection via close contact and inhalation (droplets or crusts) envelope is unstable outside of host species immunity for many strains
Poxviridae (family)
Degrees of Lesions
Macule: flat red
Papule: raised
Vesicle: clear fluid
Pustule: opaque pus
Orthopoxvirus variola
smallpox virus
initially infects the internal organs then moves out to skin
1978 last natural case, Janet Parker was last death
enveloped, polyhedral capsids, dsDNA
most prevalent DNA viruses
remains inactive inside infected cells until ready for a reoccurence
latent infections hang out in the ganglia
Herpesviridae (family)
HHV 1 - casual contact (often children)
HHV 2 - STD
Syncytia
cells with the virus fuse with adjacent cells and spread the virus
Varicella-Zoster virus
HHV 3
causes chicken pox and shingles
dsDNA, naked, icosahedral capsid
(___): benign growths (warts) on epithelium
Papillomaviridae
papillomas
seed warts
fingers and toes
cauliflower appearance
planar warts
soles of the feet
flat warts
trunk, face, knees
cauliflower appearance with a bed of red surrounding
Rhinovirus (genus)
naked, +ssRNA
It’s a cold
meds can relieve symptoms, but the symptoms are how your body fights back. you might as well just ride it out
Orthomyxovirus
enveloped, -ssRNA, segmented
flu virus
Influenza
orthomyxovirus
Morbilivirus (genus)
enveloped, unsegmented, -ssRNA
Caused by morbilivirus which infects respiratory track then spreads Characteristic lesions (Koplik's spots) in mouth
Measles
Retroviridae (family)
most studied virus group
genome contains two identical molecules of +ssRNA
polyhedral capsule with spiked envelope
Virus transcribes dsDNA from ssRNA (which is backwards to every organism on earth) [possible with reverse transcriptase]
HIV
replicates in our immune cells and destroys them
Immunity prevented because of antigenic variability with gp120 (facilitates attachment) and gp41 (fusion)
AIDS
not a disease
AIDS is any of a certain opportunistic or rare infection that:
- occurs in presence of antibodies against HIV
- a CD4 white blood cell count below 200 cells / micro-liter of blood
Treat with reverse transcirptase inhibitors and fusion inhibitors
Lytic Cycle
- Virus attaches
- Entry (injection of viral DNA)
- Virus starts to take over
- Virus chops up host chromosome and enzymes injected with DNA. Phage DNA is replicated, transcribed to RNA, and translated
- Viral proteins are made
- Assembly of viral proteins
- cell is ruptured via lysis, and the new viruses released
Lysogenic Cycle
Lysogeny happens between entry and virus take over (2 and 3)
- Host chromosome is left in tact an the viral DNA is inserted
- the bacteria grows and divides, replicating virus with it
- When virus feels threatened it chops up genome and resumes Lytic cycle
